The present invention relates to an apparatus for the automatic feeding of a carrier to a laminating station, with a gripper device which is movable to and fro horizontally.
European Patent Application No. 0,084,077 discloses an apparatus for the automatic feeding of carrier boards for printed electric circuits to a film roller mechanism, and in this apparatus there is above a board stack a holding device which is movable to and fro in a vertical direction relative to the board stack. The holding device receives two parallel horizontal guide rods carrying at their opposite ends piston/cylinder units, the piston rods of which have parallel cross-members which are arranged in a horizontal plane and on the free ends of which adjustable grippers are provided. The grippers are movable both horizontally and vertically. Arranged parallel to each cross-member is a displaceable roller table which can move in a horizontal plane out of a position of rest into a working position and vice versa. In the working position, the grippers transfer the carrier boards to the roller tables.
Carrier boards for printed circuits, after being cleaned, washed and dried, are supplied to a laminating station or to a film roller mechanism, in which a photoresist film is laminated onto the carrier board. The carrier boards are usually stacked, and it is known that the transport of the carrier boards for printed electric circuits from the stack to the laminating station presents difficulties inasmuch as the sensitive surface of the carrier boards may not be subjected to mechanical stress, to avoid scratches, indentations or impressions. The use of elastic rubber suckers also poses problems, since corresponding impressions of the rubber suckers can remain on the boards, and these can lead to soiling which could impair the reliable coating-on of the photoresist film in the roller mechanism. According to European Patent Application No. 0,084,077 mentioned above, these disadvantages are avoided by the provision of an automatic apparatus for feeding carrier boards for printed circuits to a laminating station. This feed apparatus operates with grippers which do not come into contact with the surfaces of the carrier boards, but only with the longitudinal edges of the carrier boards.
In general, such carrier boards, carriers, multi-layers or other boards to be laminated are transported from a heating station to the laminating station by means of guided fingers which rest against the rear edge of the board to be transported and which push the latter in the direction of the laminating station. Difficulties arise here when the board, because of its thinness, has only a low flexural rigidity, since this is then insufficient to guarantee that the front edge of the board will be introduced reliably into the nip between the laminating rollers of the laminating station. Because of this, the board can be drawn into the laminating station incorrectly, and this can cause damage to the board which then has to be separated out as a reject.